contents/understanding-lttng/plumbing/overview.md

   1 ---
   2 id: plumbing-overview
   3 ---
   4
   5 As [mentioned previously](#doc-installing-lttng), the whole LTTng suite
   6 is made of the LTTng-tools, LTTng-UST, and
   7 LTTng-modules packages. Together, they provide different daemons, libraries,
   8 kernel modules and command line interfaces. The following tree shows
   9 which usable component belongs to which package:
  10
  11   * **LTTng-tools**:
  12     * session daemon (`lttng-sessiond`)
  13     * consumer daemon (`lttng-consumerd`)
  14     * relay daemon (`lttng-relayd`)
  15     * tracing control library (`liblttng-ctl`)
  16     * tracing control command line tool (`lttng`)
  17   * **LTTng-UST**:
  18     * user space tracing library (`liblttng-ust`) and its headers
  19     * preloadable user space tracing helpers
  20       (`liblttng-ust-libc-wrapper`, `liblttng-ust-pthread-wrapper`,
  21       `liblttng-ust-cyg-profile`, `liblttng-ust-cyg-profile-fast`
  22       and `liblttng-ust-dl`)
  23     * user space tracepoint code generator command line tool
  24       (`lttng-gen-tp`)
  25     * `java.util.logging`/log4j tracepoint providers
  26       (`liblttng-ust-jul-jni` and `liblttng-ust-log4j-jni`) and JAR
  27       file (`liblttng-ust-agent.jar`)
  28   * **LTTng-modules**:
  29     * LTTng Linux kernel tracer module
  30     * tracing ring buffer kernel modules
  31     * many LTTng probe kernel modules
  32
  33 The following diagram shows how the most important LTTng components
  34 interact. Plain purple arrows represent trace data paths while dashed
  35 red arrows indicate control communications. The LTTng relay daemon is
  36 shown running on a remote system, although it could as well run on the
  37 target (monitored) system.
  38
  39 <figure class="img img-100">
  40 <img src="/images/docs26/plumbing-26.png" alt="LTTng plumbing">
  41 <figcaption>
  42     Control and data paths between LTTng components
  43 </figcaption>
  44 </figure>
  45
  46 Each component is described in the following subsections.